RUM(4) BSD Kernel Interfaces Manual RUM(4)
rum -- Ralink Technology USB IEEE 802.11a/b/g wireless network device
rum* at uhub? port ?
The rum driver supports USB 2.0 and PCI Express Mini Card wireless
adapters based on the Ralink RT2501USB and RT2601USB chipsets.
Ralink PCI Express Mini Card adapters show up as normal USB 2.0 devices
and are thus handled by the rum driver.
The RT2501USB chipset is the second generation of 802.11a/b/g adapters
from Ralink. It consists of two integrated chips, an RT2571W MAC/BBP and
an RT2528 or RT5226 radio transceiver.
The RT2601USB chipset consists of two integrated chips, an RT2671 MAC/BBP
and an RT2527 or RT5225 radio transceiver. This chipset uses the MIMO
(multiple-input multiple-output) technology with multiple antennas to
extend the operating range of the adapter and to achieve higher through-
These are the modes the rum driver can operate in:
BSS mode Also known as infrastructure mode, this is used when asso-
ciating with an access point, through which all traffic
passes. This mode is the default.
IBSS mode Also known as IEEE ad-hoc mode or peer-to-peer mode. This
is the standardized method of operating without an access
point. Stations associate with a service set. However,
actual connections between stations are peer-to-peer.
Host AP In this mode the driver acts as an access point (base sta-
tion) for other cards.
monitor mode In this mode the driver is able to receive packets without
associating with an access point. This disables the
internal receive filter and enables the card to capture
packets from networks which it wouldn't normally have
access to, or to scan for access points.
The rum driver can be configured to use Wired Equivalent Privacy (WEP) or
Wi-Fi Protected Access (WPA-PSK and WPA2-PSK). WPA is the current
encryption standard for wireless networks. It is strongly recommended
that WEP not be used as the sole mechanism to secure wireless communica-
tion, due to serious weaknesses in it. The rum driver relies on the
software 802.11 stack for both encryption and decryption of data frames.
The rum driver can be configured at runtime with ifconfig(8) or on boot
The following firmware file is loaded when an interface is brought up:
The following adapters should work:
3Com Aolynk WUB320g
ASUS WL-167g ver 2
Atlantis Land A02-UP1-W54
Belkin F5D7050 ver 3
Belkin F5D9050 ver 3
CNet CWD-854 ver F
Conceptronic C54RU ver 2
D-Link DWL-G122 rev C1
LevelOne WNC-0301USB v3
Linksys WUSB54G rev C
Sitecom WL-113 ver 2
The following example scans for available networks:
# ifconfig rum0 scan
The following hostname.if(5) example configures rum0 to join network
``mynwid'', using WPA key ``mywpakey'', obtaining an IP address using
The following hostname.if(5) example creates a host-based access point on
inet 192.168.1.1 255.255.255.0
rum0: error N, could not read firmware ... For some reason, the driver
was unable to read the microcode file from the filesystem. The file
might be missing or corrupted.
rum0: could not load 8051 microcode An error occurred while attempting
to upload the microcode to the onboard 8051 microcontroller unit.
rum0: device timeout A frame dispatched to the hardware for transmission
did not complete in time. The driver will reset the hardware. This
should not happen.
arp(4), ifmedia(4), intro(4), netintro(4), usb(4), hostname.if(5),
The rum driver first appeared in OpenBSD 4.0.
The rum driver was written by Niall O'Higgins <firstname.lastname@example.org> and
Damien Bergamini <email@example.com>.
The rum driver supports automatic control of the transmit speed in BSS
mode only. Therefore the use of a rum adapter in Host AP mode is dis-
Host AP mode doesn't support power saving. Clients attempting to use
power saving mode may experience significant packet loss (disabling power
saving on the client will fix this).
BSD March 24, 2017 BSD